Geographic Range

Montane harvest mice live in the dry uplands of the Great Plains. They are found in southwestern South Dakota and southeastern Montana south thruough eastern Wyoming, Colorado, and New Mexico, all of Nebraska and Kansa and most of Oklahoma and Texas. Also found in southern Arizona and northern Mexico in the extremes of its range.

Habitat

These mice appear to prefer climax, or nearly climax, well-drained grassland. They are in the highest densities in shorter grasses, but are found in lower numbers in taller grasses. Reithrodontomys montanus builds its nest out of grasses and places the nest slightly above the ground in grasses or shrubs, or on the ground. The species has also been known to take over a bird's nest for its own. In areas with human contact Reithrodontomys montanus has been found in tin cans or other suitable nests.

Physical Description

Reithrodontomys montanus is a small mouse with grayish-brown fur. It has a white underside and a dark stripe down the middle of the back. The tail of this species ranges from 20 to 69 mm and is always shorter than the head and body. The tail is also striped and has sparse fur, yet does not appear scaly. Reithrodontomys means "groove toothed mouse" and refers to a groove that is found in the upper incisors. This groove easily distinguishes this genus from others occuring in the same area.

Reproduction

Females have 6 mammae.
Males have seminal vesicals, preputial glands, ampullary glands, penial spines, and a baculum.
Young are born naked and blind. They are well haired at 6 days and their eyes open at 8 to 13 days. Adult size is reached in 5 weeks. Reithrodontomys montanus goes through 2 changes in pelage before reaching adulthood. The juvenile hair is cottony and duller in color. Sub-adult pelage is the same color as adults but the hair is less dense. Males reach sexual maturity at 2 months, while females reach sexual maturity at about 12 weeks

Conservation Status

Other Comments

This species was first discovered by Baird in 1855. The discovery was made in a mountainous region of Colorado which led to the species montanus. Later, however, its distribution was found to be the Great Plains, far from any mountains.

Contributors

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

omnivore

an animal that mainly eats all kinds of things, including plants and animals

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

tactile

uses touch to communicate

terrestrial

Living on the ground.

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

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The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

This material is based upon work supported by the
National Science Foundation
Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.